Retinal vascular occlusion, glaucoma, diabetic retinopathy and age related macular degeneration (AMD) are related to retinal ischemia. Retinal vascular occlusion includes such as central or branch retinal artery occlusion (CRAO or BRAO). The defined ocular disorders often result in serious complications. Thus, the treatment of retinal ischemic injury is vital.
Amacrines and their neuronal processes are susceptible to ischemia plus reperfusion (I/R). After I/R, the immunolabelings of vimentin/glial fibrillary acidic protein (GFAP) are enhanced in Müllers. Matrix metalloproteinase-9 (MMP-9) is proteolytic and able to degrade the extracellular matrix. Ischemia has been also shown to lead to the retinal ganglion cell (RGC) death that is associated with increased MMP-9 levels. On the other hand, HO-1 is an inducible isoform that is involved in the response to oxidative stress and hypoxia. Increased levels of HO-1 would seem to be able to provide a protective effect against retinal ischemia and/or AMD via antioxidative activity.
Mitogen-activated protein kinases (MAPKs) are key kinases in signal transduction pathways. Moreover, major members of MAPK subfamily (JNK, p38, and ERK1/2) have been implicated in neuronal injury and diseases. The MAPK protein, p38, which is stimulated by various stresses including ischemia and oxidative stress, has been shown to be involved in apoptosis.
“Chi-Ju-Di-Huang-Wan” (CJDHW; Sun Ten Pharmaceutical Co., Taipei, Taiwan) is a traditional Chinese herbal recipe which consists of the formula “Liu Wei Di Huang Wan” (Rehmanniae Radix Preparata, Corni Fructus, Rhizoma Dioscoreae, Poria, Cortex Moutan Radicis, Alismatis Rhizome) plus Fructus Lycii and Chrysanthemi Flos. Sometimes honey will be additionally added into the recipe in order to enhance flavor and make the elderly and children easy to swallow (Chang Y H, Lin H J, Li W C: Clinical evaluation of the traditional chinese prescription Chi-Ju-Di-Huang-Wan for dry eye. Phytother Res 2005, 19:349-354). “CJDHW” has been reported to be an effective treatment in dry eye. “CJDHW” is an effective stabilizer of the tear film and decreases abnormalities of the corneal epithelium. However, the therapeutic mechanism(s) associated with of the effects of CJDHW remain unknown. Active known compounds in this formula include the antioxidant zeaxanthin and lutein, which are present in Fructus Lycii and Chrysanthemi Flos, as well as trehalose, which is present in Rehmanniae Radix Preparata.